The Primitive Mosses 



Habit of flowering. Male and female flowers on the same 

 plant (monoicous). 



Veil (calyptra). Smooth, split on one side and reaching to 

 the middle of the spore-case. 



Spore-case. - - Light-brown, oval, 

 oblong, of thick texture, slightly con- 

 stricted under the mouth, wrinkled 

 lengthwise when dry. 



Dry spore-case. 



Top of spore-case 

 with peristome. 



Portion of peristome. 



Young 

 spore-case. 



Weisia viridula. 



Pedicel (seta). \ to f of an inch long and twisted to the right. 



Lid (operculum) . Beak, long, straight or bent obliquely. 



Teeth (peristome}. Orange-red, variable, slender or broad, 

 often ending abruptly (truncate) or split into two parts with 

 2 to 5 cross bars, sometimes rudimentary. 



Annulus. Narrow, persistent. 



Spores. Mature from March to May. 



Distribution. Universal. 



Genus TREMATODON, Michx. 



The species of the Genus Tremato- 

 don are short plants, sparingly branched 

 and forming pale-green or dusky-brown 

 tufts on the ground. The leaves are 

 lance-shaped, tapering toward the apex; 

 a vein is present, and the cells are large 

 and long-hexagonal. The spore-cases 

 are oblong, slightly arched with a long 

 neck (collum) once or twice as long as 

 the spore-case. They have long-beaked 

 lids with conical bases and are raised on 

 slender pedicels | to i| inches long. A 

 simple or compound annulus is present and a single row of 

 sixteen red-brown narrowly lance-shaped teeth cleft to near the 

 base into two unequal forks. 



147 



T. ambiguum. Portion of 

 peristome. 



